Hydrochloric Acid → 6-chloro-7-(2-chloro-4,5-dimethylphenoxy)-2-(trifluoromethyl)-2H-chromene-3-carboxylic acid

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Reaction Conditions

Reaction Steps

To the concd product of step 1 in a suitable vial was added 400 mg (mmole) of lithium hydroxide monohydrate, 1 mL of water, 2 mL of methanol and 7 mL of THF. The vial was capped, in an aluminum heating block and the block heated to 100° C. for 30 min. After allowing the vial to cool to rt, the mixture was treated with 5 mL of 1N HCl and 2 mL of diethyl ether. The organic layer was removed and the aqueous layer extracted two times with diethyl ether. Combined organic extracts were concd by evaporation of solvent under a stream of N2 followed by conc in vacuo to afford 150 mg (34.6%) of a yellow solid: 1H NMR (CDCl3/300 MHz) 2.26 (s, 3H), 5.64 (q, 1H, J=6.8 Hz), 6.27 (s, 1H), 6.94 (s, 1H), 7.26 (s, 1H), 7.3H (s, 1H), 11.28 (hs, 1H); MS (ES−) 431 (M−1, 100); HRMS (ES−) m/z calcd for (M−H; C19H12Cl2F3O4) 431.0059, found 431.0048.

Provenance & Evidence